In government, bicameralism is the practice of having two legislative or parliamentary chambers. Thus, a bicameral parliament or bicameral legislature is a parliament or legislature which consists of two Chambers or Houses.
The relationship between the two Chambers varies; in some cases, they have equal power, while in others, one Chamber is clearly superior in its powers. It is also commonplace in most federal systems to have a bicameral legislature, with the second chamber representing the constitutent states, such as the United States Senate
Some political scientists believe that bicameralism makes meaningful political reforms more difficult to achieve and increases the risk of deadlock (particularly in cases where both Chambers are powerful). Others argue strongly for the merits of the checks and balances provided by the bicameral model, which they believe helps prevent the passage into law of ill-considered legislation.
See also: Unicameralism, List of national legislatures